Patent Document 1 discloses a mode of a dehumidification and humidification device for a vehicle that supplies humidified air to an occupant in a vehicle interior. The device described in Patent Document 1 includes an adsorption element that is obtained by supporting an adsorbing material with an element which can ventilate air, a heater that is disposed on the non-ventilation surface of the adsorption element to directly heat the adsorption element, and a blower that can rotate forward and backward.
During winter periods in which the outside air is dry, for example, the air in a room interior is introduced into the adsorption element by rotating the blower in one direction with the energization of the heater stopped. In this case, the adsorbing material has ordinary temperature, and thus the adsorption element fulfills a adsorbing function of removing water from the air passing through the adsorption element, so that the dehumidified air is blown out to the room interior. After this adsorbing operation is carried out for a certain time, the heater is then energized and the adsorption element is heated by the heater. In response to the energization of the heater, the rotational direction of the blower is reversed to blow air in a reverse direction. Since the water desorbed from the adsorption element is contained in the blown air, humidified air is supplied to the room interior.
The water desorption from the adsorption element requires that the temperature of the adsorption element should rise or that the air having a low relative humidity should flow into the adsorption element.
As described above, at the time of desorption, the energization of the heater is begun to start heating the adsorption element. Thus, the temperature of the adsorption element cannot rise quickly at the time of desorption, taking time to increase the temperature of the adsorption element to a target temperature. The heating output of the heater needs to be made large to tentatively quickly increase the temperature of the adsorption element.
The adsorption element that has taken time to increase its temperature at the time of desorption, when switched to the adsorption mode, gradually decreases in temperature due to the stop of the energization of the heater. Thus, the adsorbing material takes time to be decreased in temperature to a target temperature. At the time of switching between desorption and adsorption, the temperature and humidity of humidified air and dehumidified air change gently similar to the temperature change of the adsorption element.